Viscosity - Temperature Calculator
Based on the Walther equation: knowing the kinematic viscosity V1 and V2 of the lubricating oil at T1 and T2 temperatures, calculate the viscosity V3 at any T3 temperature (unit: mm ²/s or cSt).
Instructions for use: ① Enter two sets of temperature-viscosity reference points (the higher the temperature, the smaller the viscosity should be); ② Enter the target temperature T3; ③ Click [Calculate] to obtain the corresponding viscosity.
cSt
cSt
Viscosity index VI calculation
According to the ASTM D2270 standard segmented formula, the viscosity index VI is calculated by the kinematic viscosity at 40 ° C and 100 ° C, or the unknown viscosity under the specified VI is solved in reverse.
Forward calculation: known 40 ℃/100 ℃ viscosity → find VI
cSt
cSt
Reverse calculation 1: Known VI, 40 ° C viscosity → reverse calculation 100 ° C viscosity
cSt
Reverse calculation 2: Known VI, 100 ° C viscosity → reverse calculation of 40 ° C viscosity
Tip: Use ASTM D2270 Formula B for extrapolation when VI ≥ 100; accuracy depends on the numerical range, and the result retains 2 decimal places.
cSt
Harmonic viscosity calculator
Support the viscosity prediction of two base oils mixed in proportion, and the reverse ratio of the given target viscosity; the temperature coefficient K is automatically adapted to the working conditions of 100 ° C/40 ° C/-5 ° C.
A Known ratio → Calculate mixing viscosity
cSt
cSt
%
B Known target viscosity → Calculate blending ratio
cSt
cSt
cSt